My 1985 190D 5 Speed (160K) seems to be slightly surging from the sound that comes from the engine. The RPM needle does not move at all but if you listen carefully you can make out the noise. I made sure all the accessories in the car were turned off so that is definitely not a culprit.

Anybody have any idea as to what it might be ? The car does run fine and starts perfectly.

Thank You

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Audi TT